"Upgrade to Pro" window, "Options" window, "Statistics" window open,
but "Navigation" window doesn't appear.
"Navigation" window don't open, I cannot do anything.
I feel this trouble has happened since I upgraded iTunes 3 to iTunes 4.

I use Mac OS 10.1.5
384M
PowerPC G3
LimeWire 3.6.15
iTunes 4(Japanese)

Would you tell me how to fix this problem?